Plastic spring toggle action

ABSTRACT

A toggle mechanism for a switch is provided adapted for switches operating at relatively low amperages of one ampere or less. The toggle has a lever supported in pivoting relation in a support frame at its mid-section and oppositely extending arm and trigger handle. A plastic strip extends from the mid-section to the support frame and provides the over center action of the toggle mechanism.

United States Patent Fontana [54] PLASTIC SPRING TOGGLE ACTION [72] Inventor: Anthony J. Fontana, Warwick, R].

[73] Assignee: General Electric Company [22] Filed: Oct. 22, 1971 [21] Appl. No.: 191,730

52 us. Cl. ..200/172 R, 200/67 0 A [51] Int. Cl. ..H0lh 3/04 [58] Field of Search...200/67 A, I72 R, 67 G, I68 C, 200/167 A, 153 T [56] References Cited UNITED STATES PATENTS 3,409,749 11/1968 Judd et al. ..200/67 G 3,403,237 9/1968 Wysong ..200/172 R [451 Sept. 26, 1972 3,582,584 6/1971 Best ..200/168 C X 3,309,487 3/1967 Fisher ..200/l72 R 3,519,776 7/1970 Slater ..200/172 R X 3,457,383 7/1969 Roberts, Jr. et al ..200/67 A Primary Examiner-H. 0. Jones Attorney-Frank L. Neuhauser et al.

[57] ABSTRACT A toggle mechanism for a switch is provided adapted vfor switches operating at relatively low amperages of one ampere or less. The toggle has a lever supported in pivoting relation in a support frame at its mid-sec tion and oppositely extending arm and trigger handle. A plastic strip extends from the mid-section to the support frame and provides the over center action of the toggle mechanism.

2 Claims, 11 Drawing Figures PATENTED SEP 2 6 I972 SHEET 1 0F 2 FIGZ FIG. 1

FIG.3

PLASTIC SPRING TOGGLE ACTION the same assignee as this application. This switch mechanism is particularly suitable for use in articles such as night lights in which relatively low wattages are to be controlled by a small switch built directly into the night light base.

An essential mechanism for operating low wattage switches, or any switches for that matter, is the mechanical drive mechanism by which the electrical elements which conduct the electric power are positioned in at least two positions at rest. conventionally toggle mechanisms such as that taught in the above patent operate by a snap action to two stable or at rest positions one for the on or conducting condition of the electrical parts of the switch and a second for the off or mechanically separated condition of certain electrical parts of the switch.

Coil springs have been used in the past in providing the over center or snap action of the toggle mechanism of switches. Where smaller toggle mechanisms are employed as in a switch mechanism of a relatively small size such as may be incorporated in the base of a night light the use of coil springs and toggle mechanisms of conventional design is difficult and somewhat awkward.

Where simplified metal spring elements such as the alpha spring of US. Pat. No. 3,178,530 is employed problems of service life of the spring element arise and the number of switches which fail increases.

Other remedies which improve the service life expectancy of simple metal spring elements include increasing the quality and durability of the metal spring elements but there is a resultant increase in cost of the spring element, and of the switch mechanism, which is not consistant with the nature of the product in the sense that is a mass production product made available to the public with reliable switch action but at very low prices.

The switch mechanism taught in US. Pat. No. 3,457,383 provided one solution to this problem in that it provided a low cost reliable switch mechanism with simple metal spring element having extended life expectancy. An entirely distinct and novel solution to the problem has now been discovered involving use of plastic strip elements to achieve the over center toggle action.

Accordingly one object of the present invention is to provide a toggle mechanism. Of simple low cost construction.

Another object is to provide a toggle mechanism which is simpler to assemble and has lower assembly COSI.

Still another object is to provide a toggle mechanism which is safer for use in a switch mechanism in having fewer metal parts which can become broken and dislodged.

A further object is to reduce the cost and increase the reliability of small toggle mechanism for use in electrical switching.

A still further object is to provide an improved lower cost compact switch mechanism.

An additional object is to provide a more reliable safer switched night light base.

Other objects will be in part apparent and in part pointed out in the description which follows taken in conjunction with the accompanying drawings in which:

FIG. 1 is a frontelevation of a night light article including a diffuser and base.

FIG. 2 is an exploded view of the night light article of FIG. 1 having some parts shown in phantom.

FIG. 3 is a top plan view of a novel toggle lever element provided pursuant to this invention.

FIGS. 4, 5, and 6 are top plan views of the toggle lever of FIG. 3 illustrating three positions of its over center movement.

FIG. 7 and 8 are front elevations in part in section illustrating the switch mechanism in place in the base of a night light as illustrated in FIG. 1.

FIG. 9 is an exploded view of an alternative form of i toggle motion has been completed.

In one of its broader aspects the objects of the present invention are achieved by an over center toggle mechanism comprising atoggle lever said lever having a mid-section, and a handle section and an arm section extending in different directions from said mid-section,

said lever being mounted in pivotable relation in a support frame,

a self-supporting resilient plastic strip supported at one end thereof at said mid-section and at the other end thereof at said support frame and having a length greater than the distance between said supports,

said strip extending in the direction of extension of said arm and being contacted by said arm, on alternative sides thereof responsive to pivoting of said lever,

whereby an over center motion of said lever is achieved as said lever is pivoted about its mid-section.

Referring now first to FIG. 1 a night light is illustrated having an upper snap on diffuser 20 and a conforming base 22. The form of the diffuser may be changed but this is not material to the present invention the invention being concerned rather with the mechanism within base 22. The particular form of diffuser shown is the subject of US. Design Pat. No. 205,371 assigned to the same assignee as this application.

The front half 22 of the insulating housing of the night light base is provided with a trigger slot 24 and has a handle or trigger 26 extending through the slot to the base exterior. This is to permit manual manipulation of the handle to operate the switch mechanism within the base.

lower part of FIG. 2.

A trigger opening 24 extending through base 22 is formed in the forward insulating wall of the base and has the two trunion wells 34 and 36 (seen in phantom) to receive the respective trunions38 and 40 of lever 42.

Lever 42 has a mid-section at which the trunions are located so that pivot motion of the lever is about an axis extending between the trunions.

The lever 42 also has a handle or trigger portion 44 extending out from the mid-section and this is the portion which extends through trigger opening 24 of the base housing member 22 to permit manipulation of the lever from the night light exterior.

In addition lever 42 has an arm in this case a bifurcated arm portion 46 extending out from the mid-section. In the lever 42 illustratively shown the arm extends in a direction generally opposite to the direction of extension of handle 44.

Lever 42 also has a self-supporting through resilient strip 50 supported at the mid-section of the lever. 42 and in this illustrative embodiment formed integrally with the lever as seen more clearly in FIG. 3.

The electrical contact strips 52 and 54 which furnish power to the base of lamp bulb 32 are shown in phantom in their relation to the bulb. These same contact strips are shown also in solid lines mounted in the back half 60 of the night light base.

Contact strip 54 is positioned to deliver power received from a conventional electrical receptacle through a power blade 62 along oneside of the insulating housing and to the screw shell of a lamp bulb such as 32. Strip 54 remains stationary within the housing and is in continuous electrical contact with the inner end 63 of power blade 62. 4

Contact strip 52 is positioned at the opposite side of the housing and delivers power intermittently as it is received from the inner end 65 of power blade 64 depending on whether the contact strip touches the inner end 65 of blade 64 or whether it is spaced from it.

The make and break operation of the electrical .con-

tact is best explained with reference to FIGS. 7 and 8.

These figures are views of the night light base as seen in FIG. 1 but with the front half portion 22 of the insulating housing mostly broken away and removed. The rear half of the base housing is accordingly visible and this corresponds to the housing as seen in perspective in the lower section of FIG. 2.

Referring first to FIG. 8 the contact strips 52 and 54 are shown in an at rest position corresponding to the position they occupy in FIG. 2. Contact 52 has a lower end which is U shaped having the lower cross member 56 and the upright end section 58.

The lever is seen in section as-it extends through the plane between the front and back halves of the housing. What is seen is the arms 46 and 48 and also the strip 50. The strip 50 extends into groove 70 and by its inherent spring like action urges the lever arms to the position shown with the arms extending freely through the U at the lower portion of contact strip 52 and making no contact with it. Strip 52 rests against and in electrical contact with the inner end 65 of blade 64 in the on position.

This is the positive essentially as shown in FIG. 6 with the strip 50 extending from the mid-section of the lever intothe groove formed within the support frame of the insulating housing. The line 8-8 of FIG. 6 indicates approximately the line along which the lever is section to present the view seen in FIG. 8.

- The break or open position of the switch is that illustrated in FIG. 7 and the position of the lever corresponds to that illustrated in FIG. 4. With reference first to FIG. 7 the contact strip 52 is seen to be spaced from the inner end 65 of a power blade. The end upright 58 of the contact strip 52 is urged to the right by the prong 48 of the bifurcated arm 46,48 of the lever. This action of the lever arm on the contact strip 52 to urge itinto the open or off position is similar to the like action of the mechanism as taught in U.S. Pat. No. 3,457,383 referenced above.

What is quite distinct and novel in the mechanism of the present invention is the toggle mechanism by which the switch is actuated and controlled. This is explained best first with reference to the FIGS. 4, 5, and 6 and then with reference to FIGS. 9, 10, and 11.

Referring first now to FIG. 4 the lever is seen to have the handle 44, trunion 38, strip 50 and bifurcated arm or fork 46, 48. The trunion at the lever mid-section is supported in pivotable relation in the support frame or housing seen best in FIG. 2. The end 51 of strip 50 nests in the notch or groove 70 in another portion of the support frame or housing in this illustration an integral portion of the back half 60 of the insulating base of the night light.

As shown the length of strip 50 is greater than the distance between the mid-section of the lever and the bottom of groove 70. Accordingly it occupies a curved path extending from the lever mid-section to the groove. Normally the strip is under compression in its at rest positions shown in FIGS. 4 and 6. When the lever is pivoted from one at rest position to the other the compression is increased and an over center or snap like pivot motion is imparted to the lever to bring it or return it to an at rest position. This is illustrated from FIG. 5.

Referring now to this figure it is evident that as the handle 44 is pivoted from the position shown in FIG. 4 to the position of FIG. 5 the compressive forces acting along the strip will be increased tending to resistthe handle movement and tending to return the handle to the at rest position of FIG. 4. As the handle approaches the center, however, the forked arm and particularly a boss 49 extending up from the prong 48 into the path of the strip is brought into contact with and delivers a lateral force to the strip at some intermediate point along its length. This combined pivoting of the lever and lateral force on the strip increases the compressive force acting along the strip and in effect builds up a force which will serve as a driving force to drive the lever back into its initial at rest "position or by an over center movement into the at rest position shown in FIG. 6.

An alternative form in which the toggle mechanism of this invention may be employed is illustrated in FIGS. 9, 10, and 11. FIG. 9 is an exploded view of the elements including the lever having the mid-section where the lever is" supported in pivotable relation by trunion 89, the handle 84 extending from the mid-section and the forked arm 85 having prongs 86 and 88 extending in another direction from the mid-section.

A separate self-supporting resilient plastic strip is seen poised to be positioned in longitudinally compressed relation between notch 87 between prongs 86 and 88 and the groove 92 in frame support member 94.

When the frame members supporting the notch 92 and trunion 89 are brought together the strip 90 is put under compression and assumes the curved shape shown in FIG. 11 because the distance between lever mid-section and notch is shorter than the length of strip 90.

Increased compression results from pivoting the toggle lever and gives the strip 90 a sinuous shape leading up to the over center acceleration of pivot movement of the lever toward its other at rest position.

In this case it is the forks themselves which impart the lateral force to the strip and cause it to described the over center type of motion. In other words the strip is located directly between the prongs of the forked arm so that pivoting of the lever and snapping over center motion of the strip all occur in the same plane.

By contrast in the device of FIGS. 4, 5, and 6 the forked arm sweeps through an angle in a lower plane and the strip formed integrally with the lever moves in a plane above the forked arms. The bosses 47 and 49 which are part of the prongs of the forked arm impart the lateral force to the strip which develops sufficient increased compression to generate the over center acceleration of the lever to this alternate at rest position. Any means which applies lateral force to a mid-section of the strip and permits a released acceleration of the strip to its alternative at rest position will suffice in practising the present invention.

The-form of strip used in connection with the device of FIGS. 9, l0, and 11 makes it possible to employ a more rigid plastic in forming the lever element and a more pliable plastic in forming the strip.

One advantage made possible by the present invention is that no metal spring parts may be formed due to breakage and failure of a metal spring and movement of these parts into a position to cause shorting of the flow of current in the night light or other device in which such a toggle mechanism is employed. All parts of the toggle mechanism may be insulating plastics parts thus eliminating the potential hazard of shorting.

A further advantage is that the toggle mechanism particularly that of FIGS. 4, 5, and 6 has fewer parts than previously used mechanisms and thus has lower cost both in manufacture of the smaller number of parts and also in the assembly of the whole mechanism from the smaller number of parts.

Nylon plastic has been found highly satisfactory in forming the lever with integral plastic spring as illustrated in FIG. 3.

What is claimed is:

1. An over center toggle mechanism comprising a to le lever sai ever having a mid-section and a handle and an arm extending in different directions from said mid-section,

said lever being mounted at its mid-section in pivotable relation in a support frame,

a self-supporting resilient plastic strip,

said strip being supported at one end at the mid-section of said lever and at the other end thereof at another portion of said support frame,

the length of said strip being greater than the distance between said supports,

said strip extending in the direction of extension of said arm,

and said arm having means for imparting lateral motion to said strip as said lever is pivoted.

2. The article of claim 1 in which the strip is formed integrally with said lever. 

1. An over center toggle mechanism comprising a toggle lever said lever having a mid-section and a handle and an arm extending in different directions from said mid-section, said lever being mounted at its mid-section in pivotable relation in a support frame, a self-supporting resilient plastic strip, said strip being supported at one end at the mid-section of said lever and at the other end thereof at another portion of said support frame, the length of said strip being greater than the distance between said supports, said strip extending in the direction of extension of said arm, and said arm having means for imparting lateral motion to said strip as said lever is pivoted.
 2. The article of claim 1 in which the strip is formed integrally with said lever. 